Sleeping baby

UPDATE ****I brought my baby to the doctor and I found out the reason he’s been all over the place is my 5 month old has tonsillitis 🙈🙈🙈******

I have a 5 month old who all of a sudden has stopped sleeping when put into his crib and will only sleep I’d being held. We would rock him to sleep and as soon as he’s out into his crib he wakes up. He only had one nap today and he’s wrecked but won’t sleep?? I don’t know why???